Wireless device charger with cooling device

ABSTRACT

A wireless device charger configured to produce an alternating magnetic field, thereby inducing an alternating electrical current within a capture coil of a personal electronic device proximate to the wireless device charger, said wireless device charger includes a source coil having a ferrite element configured to generate the alternating magnetic field, a housing formed of a thermally conductive material in thermal communication with the ferrite element, and an air movement device configured to produce an air flow across a surface of the housing flowing from an air inlet to an air outlet, thereby reducing a housing temperature. The surface of the housing defines a plurality of fins extending along the housing in a direction of the air flow. At least one fin in the plurality of fins has a non-symmetric surface, thereby creating turbulence in the air flow.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application and claims benefit under 35 U.S.C. §120 of U.S. patent application Ser. No. 16/917,058, filed Jun. 30, 2020,which claimed benefit under 35 U.S.C. § 120 of U.S. patent applicationSer. No. 16/241,142, filed Jan. 7, 2019, which claimed benefit under 35U.S.C. § 119(e) of U.S. Provisional Patent Application No. 62/615,193filed on Jan. 9, 2018, the entire disclosure of each of which is herebyincorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The invention generally relates to wireless device chargers and moreparticularly to a wireless device charger having a cooling device toremove heat from the assembly.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The present invention will now be described, by way of example withreference to the accompanying drawings, in which:

FIGS. 1 a and 1 b are perspective views of a wireless device charger(WDC) in accordance with a first embodiment of the invention;

FIG. 2 is a perspective view of a WDC in accordance with a secondembodiment of the invention;

FIG. 3 is a perspective view of a WDC in accordance with a thirdembodiment of the invention;

FIG. 4 is a perspective view of a WDC in accordance with a fourthembodiment of the invention;

FIG. 5 is a perspective view of a WDC in accordance with a fifthembodiment of the invention;

FIG. 6 is a perspective view of a WDC in accordance with a sixthembodiment of the invention;

FIG. 7 is an exploded view of the WDC of FIGS. 1 a and 1 b in accordancewith the first embodiment of the invention;

FIG. 8 is a chart of the materials used to form the components of theWDC of FIGS. 1 a and 1 b in accordance with the first embodiment of theinvention;

FIG. 9 is an alternative perspective view of the WDC of FIG. 2 inaccordance with the second embodiment of the invention;

FIG. 10 a is top view of the WDC of FIG. 2 in accordance with the secondembodiment of the invention;

FIG. 10 b is a side view of the WDC of FIG. 2 in accordance with thesecond embodiment of the invention;

FIG. 10 c is a right end view of the WDC of FIG. 2 in accordance withthe second embodiment of the invention;

FIG. 10 d is a bottom view of the WDC of FIG. 2 in accordance with thesecond embodiment of the invention;

FIG. 10 e is a left end view of the WDC of FIG. 2 in accordance with thesecond embodiment of the invention;

FIG. 10 f is a left end view of the WDC of FIG. 2 with the air ductremoved in accordance with the second embodiment of the invention;

FIG. 11 is a cross section side view of the WDC of FIG. 2 in accordancewith the second embodiment of the invention;

FIG. 12 is a cross section top view of the WDC of FIG. 2 showing anonlinear fin in accordance with the second embodiment of the invention;

FIG. 13 is a cross section top view of the WDC of FIG. 2 showing asurface enhancement in accordance with the second embodiment of theinvention;

FIG. 14 is an end view of an air inlet of the WDC of FIG. 2 inaccordance with the second embodiment of the invention;

FIG. 15 is an end view of an air exhaust of the WDC of FIG. 2 inaccordance with the second embodiment of the invention;

FIG. 16 a is perspective of the WDC of FIG. 3 in accordance with thethird embodiment of the invention;

FIG. 16 b is a side view of the WDC of FIG. 3 in accordance with thethird embodiment of the invention;

FIG. 17 a is a bottom view of the WDC of FIG. 3 in accordance with thethird embodiment of the invention;

FIG. 17 b is a top view of the WDC of FIG. 3 in accordance with thethird embodiment of the invention;

FIG. 18 a is a side view of a blower and air duct of the WDC of FIG. 3in accordance with the third embodiment of the invention;

FIG. 18 b is an end view of a blower and air duct of the WDC of FIG. 3in accordance with the third embodiment of the invention;

FIG. 18 c is a perspective view of a blower and air duct of the WDC ofFIG. 3 in accordance with the third embodiment of the invention;

FIG. 19 a is a top perspective view of the WDC of FIG. 4 in accordancewith the fourth embodiment of the invention;

FIG. 19 b is a bottom perspective view of the WDC of FIG. 4 inaccordance with the fourth embodiment of the invention;

FIG. 19 c is a perspective end view of the WDC of FIG. 4 in accordancewith the fourth embodiment of the invention;

FIG. 19 d is a top perspective view of the WDC of FIG. 4 with a topcover removed in accordance with the fourth embodiment of the invention;

FIG. 19 e is side cut away view of the WDC of FIG. 4 in accordance withthe fourth embodiment of the invention;

FIG. 20 a is a top perspective view of the WDC of FIG. 5 in accordancewith the fifth embodiment of the invention;

FIG. 20 b is a bottom perspective view of the WDC of FIG. 5 inaccordance with the fifth embodiment of the invention;

FIG. 20 c is side cut away view of the WDC of FIG. 5 in accordance withthe fifth embodiment of the invention;

FIG. 21 a is a top perspective view of the WDC of FIG. 6 in accordancewith the sixth embodiment of the invention;

FIG. 21 b is a bottom perspective view of the WDC of FIG. 6 inaccordance with the sixth embodiment of the invention;

FIG. 21 c is a side cut away view of the WDC of FIG. 6 in accordancewith the sixth embodiment of the invention;

FIG. 21 d is an end view of the WDC of FIG. 6 in accordance with thesixth embodiment of the invention;

FIG. 22 a bottom perspective view of the WDC of FIG. 6 in accordancewith the sixth embodiment of the invention;

FIG. 22 b is a top perspective view of the WDC of FIG. 6 with the topcover removed in accordance with the sixth embodiment of the invention;

FIG. 22 c is a side cut away view of the WDC of FIG. 6 in accordancewith the sixth embodiment of the invention;

FIG. 22 d is a bottom perspective view of the WDC of FIG. 6 inaccordance with the sixth embodiment of the invention;

FIG. 23 is cross section view of the WDC of FIG. 2 showing air flowthrough the WDC in accordance with the second embodiment of theinvention;

FIG. 24 is cross section view of the WDC of FIG. 3 showing air flowthrough the WDC in accordance with the third embodiment of theinvention;

FIG. 25 is cross section view of the WDC of FIG. 4 showing air flowthrough the WDC in accordance with the fourth embodiment of theinvention;

FIG. 26 is cross section view of the WDC of FIG. 5 showing air flowthrough the WDC in accordance with the fifth embodiment of theinvention; and

FIG. 27 is cross section view of the WDC of FIG. 6 showing air flowthrough the WDC in accordance with the sixth embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings. In the following detaileddescription, numerous specific details are set forth in order to providea thorough understanding of the various described embodiments. However,it will be apparent to one of ordinary skill in the art that the variousdescribed embodiments may be practiced without these specific details.In other instances, well-known methods, procedures, components,circuits, and networks have not been described in detail so as not tounnecessarily obscure aspects of the embodiments.

Lithium-ion batteries used within today's personal electronic devices(PEDs) have established limits to protect the PED battery from beingexposed to excessive temperatures. Japan Electronics and InformationTechnology Industries Association (JEITA) has established guidelines forimproving battery charging safety by setting this upper temperaturethreshold at 60° C. Typical PED charging temperatures range between −10°C. to +60° C.

The Wireless Power Consortium (WPC) has released a Medium Power (MP)specification with received powers up to 60 watts (W), and have anEnhanced Power (EP) subset for receivers to accept up to 15 W, whichwill match USB fast charging capability for a wired connecting to thecharger. This EP subset is beneficial to automotive battery chargers sowireless fast charging can match plugged in capability of a USB cable.Original equipment manufacturers (OEMs) of motor vehicles are nowdemanding this capability. This invention will improve PED chargingperformance by removing or redistributing heat within a wireless devicecharger (WDC), thereby extending the amount of time for PED chargingoperation and providing a higher state of charge (SOC) over a shortertime period by eliminating charging interruption due to exceeding thetemperature threshold. This is critical to PED charging especially ifPED has an excessively low SOC.

Volumetric space for electronic components, such as a WDC, is limited inan automotive environment. The WDC is configured to move air within anenclosed space and/or move air from the heating, ventilation, and airconditioning (HVAC) duct through the WDC and, more particularly, acrossthe heat generating components of the WDC. This invention, in variousembodiments, will provide air movement within the tight vehiclepackaging space that will allow the PED surface temperature to remainbelow a threshold where PEDs will typically shutdown battery charging toreduce temperatures within the PED.

FIGS. 1-6 illustrate multiple embodiments of the WDC with differentelectrical connection configurations.

FIG. 7 illustrates a first embodiment of the WDC having a top cover 100and screws 101 configured to secure the top cover 100 to a bottom cover107. The WDC also includes a near field communication (NFC) printedcircuit board assembly (PCBA) that is configured to communicate with aportable electronic device (PED) (not shown) that is charged by the WDC.The source coils 104 having a ferrite element 109 that are used togenerate an alternating magnetic field are in direct contact with ahousing 105 that is formed of a thermally conductive material, such as acast aluminum. The housing 105 serves as a heat sink to draw heat awayfrom the source coils 104 and the ferrite element 109. The source coils104 and the ferrite element 109 are surrounded by a dielectric spacer103. The WDC further contains a control PCBA 106 that includeselectronic components that generate the alternating current supplied tothe source coils 104 as well as controller circuitry configured tocontrol the charging process and communicate with the PED via the NFCPCBA 102. Examples of materials used to form the various components ofthe WDC are shown in FIG. 8 . Variations of these components may be usedin any of the various embodiments of the WDC.

FIGS. 9-15 illustrate a second embodiment of the WDC that furtherincludes an air movement device, such as a fan or blower 120 and an airduct that is configured to redirect the air from the blower 120 throughthe WDC from the air inlet 105 a shown in FIG. 14 to the air exhaust 105b shown in FIG. 15 . Packaging of the WDC is intended to optimize blower120 placement and the radius of the air duct 110 to route air flow withleast air resistance into the WDC internal chamber in direct contactwith the housing 105 surfaces. The radius of the air duct 110 isselected to minimize the amount of height added to the WDC toaccommodate the air duct 110. The air duct 110 is created such that theradius is identical to half of the complete thickness of the WDC and theblower 120 thus reducing the air pressure drop through the air duct 110by reducing air turbulence. Applying air pressure at the air inlet 105a, air flow will traverse from the air inlet 105 a to the air exhaust105 b. Air flow will increase heat transfer from the housing 105 to theair within the WDC. Directed air flow along the longitudinal axis of theWDC creates the largest surface area and, without subscribing to anyparticular theory of operation, the heat transfer from the housing 105is directly proportional to the length of the surface of the housing105.

The second embodiment includes a plurality of posts 107 a extending froman external surface of the bottom cover 107. Without subscribing to anyparticular theory of operation, these posts 107 a draw additional heatfrom the WDC by conduction.

This second embodiment increases surface area of the housing by defininga geometry of extending contiguous metal fins 130 to the underside ofthe housing 105 along the line of forced air flow. The heat generatingcomponents, the source coils 104, and the ferrite element 109, arearranged opposite to this surface and transfer heat to the surfacesexposed to direct air flow.

The laminar air flow across the housing surface is disturbed to createairflow turbulence that impinges upon the housing 105 to increase heattransfer from the metal housing to the air flow through the WDC. Oneexample of creating turbulent air flow is accomplished by adding atleast one fin 130 a that have a non-symmetric surface, e.g., fins 130 athat extend in a nonlinear or longitudinal zig-zag pattern from inletend to exhaust end as shown in FIG. 12 . Another method of creatingturbulent air flow is by roughening the fin surface 130 b, e.g., bysandblasting the fin surface 130 b, also shown in FIG. 13 .

FIGS. 16 a-18 c illustrate a third embodiment of the WDC incorporating aseparate blower housing 140 containing the blower 120.

FIGS. 19 a-19 e illustrate a fourth embodiment of the WDC incorporatinga separate blower housing extension 150 containing the blower 120 a anda plurality of fins 130 c extending from the housing 105.

FIGS. 20 a-20 c illustrate a fifth embodiment of the WDC having ahousing 160 and blower 120 a placement that is in-line to route air flowinto the WDC internal chamber in direct contact with heat sourcesurfaces with reduced air flow resistance and a plurality of fins 130 dextending from the housing 105. The design minimizes the height of theWDC for packaging.

The enclosed air flow space can be sealed from the electronics of theWDC for highest degree of protection per the International Organizationfor Standardization (ISO) Standard 20653:2013. FIGS. 21 a-21 d and 22a-22 d illustrate a sixth embodiment of the WDC having a housing 170, ablower 120 a capable of meeting IP code IP5K2 for enclosures ofelectrical equipment as defined by ISO 20653:2013, which describesprotection from dust and liquid intrusion. This embodiment will allowfor providing IP5K2 level of sealing while still maintaining airflow tospecific heat generating components. This embodiment also includes aplurality of fins 130 e extending from the housing 105.

FIGS. 23 through 27 illustrate the air flow through the variousembodiments of the WDC.

Blower speed may be modulated through by measuring the temperature ofthe WDC components or PED components and adjusting the blower speed foroptimum cooling by airflow. Temperatures regulated with applied airflowprovide improved PED charging levels and extend charging times even withhigh ambient temperatures, e.g. exceeding 40° C., within the vehicle.

The blower is preferably oriented for optimum noise reduction tooperator. Any rotating components, such as the blower 120 may generateaudible noise at normal operating speeds. The location and orientationof the blower in the various embodiments is selected to minimize adirect noise path from the blower to the top surface of the WDC. Thiswill limit blower noise transfer to operator.

As mentioned above, this invention optimizes the PED charging surfacetemperatures by removing or redistributing heat within the module andthereby lowering PED charging surface temperatures. The result oflowering module surface temperatures is that it will extend PED chargingtimes, thereby enhancing user experience by providing more reliablecharging and reduced charging times. The automotive packagingenvironment is extremely tight even when trying to package a WDC. HVACducts that typically are located underneath or around the batterycharger, if located within the center console area, contribute to higherWDC temperatures which limit air movement below the PED chargingsurface.

Accordingly, a wireless device charger (WDC) is provided. The WDCincludes a fan, blower, or other air movement device to cool thecomponents within the WDC to reduce heating of a personal electronicdevice (PED) being charged by the WDC, thereby reducing the chances of athermal shutdown of the PED that would increase charging time of thebattery in the PED.

While this invention has been described in terms of the preferredembodiments thereof, it is not intended to be so limited, but ratheronly to the extent set forth in the claims that follow. For example, theabove-described embodiments (and/or aspects thereof) may be used incombination with each other. In addition, many modifications may be madeto configure a particular situation or material to the teachings of theinvention without departing from its scope. Dimensions, types ofmaterials, orientations of the various components, and the number andpositions of the various components described herein are intended todefine parameters of certain embodiments and are by no means limitingand are merely prototypical embodiments.

Many other embodiments and modifications within the spirit and scope ofthe claims will be apparent to those of skill in the art upon reviewingthe above description. The scope of the invention should, therefore, bedetermined with reference to the following claims, along with the fullscope of equivalents to which such claims are entitled.

As used herein, ‘One or more’ includes a function being performed by oneelement, a function being performed by more than one element, e.g., in adistributed fashion, several functions being performed by one element,several functions being performed by several elements, or anycombination of the above.

The terminology used in the description of the various describedembodiments herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used in thedescription of the various described embodiments and the appendedclaims, the singular forms “a”, “an” and “the” are intended to includethe plural forms as well, unless the context clearly indicatesotherwise. It will also be understood that the term “and/or” as usedherein refers to and encompasses any and all possible combinations ofone or more of the associated listed items. It will be furtherunderstood that the terms “includes,” “including,” “comprises,” and/or“comprising,” when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, integers, steps, operations, elements, components,and/or groups thereof.

While terms of ordinance or orientation may be used herein, theseelements should not be limited by these terms. All terms of ordinance ororientation, unless stated otherwise, are used for purposesdistinguishing one element from another, and do not denote anyparticular order, order of operations, direction or orientation unlessstated otherwise.

The invention claimed is:
 1. A wireless device charger configured toproduce an alternating magnetic field, thereby inducing an alternatingelectrical current within a capture coil of a personal electronic deviceproximate to the wireless device charger, said wireless device chargercomprising: a source coil having a ferrite element configured togenerate the alternating magnetic field; a housing formed of a thermallyconductive material adjacent to the source coil, the source coildisposed on an outer side of the housing, the housing forming an airduct inside of the housing that constrains an air flow from an air inletto an air outlet; an air movement device configured to produce the airflow through the inside of the housing flowing from the air inlet to theair outlet, thereby reducing a temperature of the housing, wherein thehousing defines a plurality of fins extending along the inside of thehousing in a direction of the air flow and wherein at least one fin inthe plurality of fins has a non-symmetric surface, thereby creatingturbulence in the air flow.
 2. The wireless device charger in accordancewith claim 1, wherein the ferrite element is in direct contact with thehousing.
 3. The wireless device charger in accordance with claim 1,wherein the housing is formed of an aluminum material.
 4. The wirelessdevice charger in accordance with claim 1, wherein the non-symmetricsurface of the at least one fin in the plurality of fins extends in anonlinear or longitudinal zigzag pattern along the housing in thedirection of the air flow.
 5. The wireless device charger in accordancewith claim 1, wherein the surface of the plurality of fins is roughened.6. The wireless device charger in accordance with claim 5, wherein thesurface of the plurality of fins has a sandblasted surface.
 7. Thewireless device charger in accordance with claim 1, wherein the airinlet is substantially perpendicular to the air outlet and wherein thewireless device charger further comprises the air duct configured toredirect the air flow from the air inlet to the air outlet.
 8. Thewireless device charger in accordance with claim 7, wherein the air ducthas a semicircular cross section and wherein a radius of the air duct issubstantially equal to a half of a thickness of the wireless devicecharger.
 9. The wireless device charger in accordance with claim 1,wherein the wireless device charger further comprises controllercircuitry configured to modulate the air flow from the air movementdevice based on a temperature of the personal electronic device.
 10. Thewireless device charger in accordance with claim 1, wherein the insideof the housing is separated from the source coil including the ferriteelement.
 11. The wireless device charger in accordance with claim 1,wherein the inside of the housing is sealed from the source coilincluding the ferrite element.